/*
 * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.file;

import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.charset.CharsetDecoder;

import javax.lang.model.element.Modifier;
import javax.lang.model.element.NestingKind;
import javax.tools.FileObject;
import javax.tools.JavaFileObject;

import com.sun.tools.javac.util.BaseFileManager;

/**
 * <p>
 * <b>This is NOT part of any supported API. If you write code that depends on
 * this, you do so at your own risk. This code and its internal interfaces are
 * subject to change or deletion without notice.</b>
 */
public abstract class BaseFileObject implements JavaFileObject {
	protected BaseFileObject(JavacFileManager fileManager) {
		this.fileManager = fileManager;
	}

	/**
	 * Return a short name for the object, such as for use in raw diagnostics
	 */
	public abstract String getShortName();

	@Override
	public String toString() {
		return getClass().getSimpleName() + "[" + getName() + "]";
	}

	public NestingKind getNestingKind() {
		return null;
	}

	public Modifier getAccessLevel() {
		return null;
	}

	public Reader openReader(boolean ignoreEncodingErrors) throws IOException {
		return new InputStreamReader(openInputStream(),
				getDecoder(ignoreEncodingErrors));
	}

	protected CharsetDecoder getDecoder(boolean ignoreEncodingErrors) {
		throw new UnsupportedOperationException();
	}

	protected abstract String inferBinaryName(Iterable<? extends File> path);

	protected static JavaFileObject.Kind getKind(String filename) {
		return BaseFileManager.getKind(filename);
	}

	protected static String removeExtension(String fileName) {
		int lastDot = fileName.lastIndexOf(".");
		return (lastDot == -1 ? fileName : fileName.substring(0, lastDot));
	}

	protected static URI createJarUri(File jarFile, String entryName) {
		URI jarURI = jarFile.toURI().normalize();
		String separator = entryName.startsWith("/") ? "!" : "!/";
		try {
			// The jar URI convention appears to be not to re-encode the jarURI
			return new URI("jar:" + jarURI + separator + entryName);
		} catch (URISyntaxException e) {
			throw new CannotCreateUriError(jarURI + separator + entryName, e);
		}
	}

	/**
	 * Used when URLSyntaxException is thrown unexpectedly during
	 * implementations of (Base)FileObject.toURI().
	 */
	protected static class CannotCreateUriError extends Error {
		private static final long serialVersionUID = 9101708840997613546L;

		public CannotCreateUriError(String value, Throwable cause) {
			super(value, cause);
		}
	}

	/**
	 * Return the last component of a presumed hierarchical URI. From the scheme
	 * specific part of the URI, it returns the substring after the last "/" if
	 * any, or everything if no "/" is found.
	 */
	public static String getSimpleName(FileObject fo) {
		URI uri = fo.toUri();
		String s = uri.getSchemeSpecificPart();
		return s.substring(s.lastIndexOf("/") + 1); // safe when / not found

	}

	// force subtypes to define equals
	@Override
	public abstract boolean equals(Object other);

	// force subtypes to define hashCode
	@Override
	public abstract int hashCode();

	/** The file manager that created this JavaFileObject. */
	protected final JavacFileManager fileManager;
}
